CVE-2026-64440 (GCVE-0-2026-64440)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:51 – Updated: 2026-08-17 04:55
VLAI
Title
staging: rtl8723bs: fix OOB write in HT_caps_handler()
Summary
In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB write in HT_caps_handler() HT_caps_handler() iterates pIE->length bytes and writes into HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct HT_caps_element). Because pIE->length is a raw u8 from an over-the-air 802.11 AssocResponse frame and is never validated, a malicious AP can set it up to 255, causing up to 229 bytes of out-of-bounds writes into adjacent fields of struct mlme_ext_info. Truncate the iteration count to the size of HT_caps.u.HT_cap using umin() so that data from a longer-than-expected IE is silently ignored rather than written out of bounds, preserving interoperability with APs that pad the element. An early return on oversized IEs was considered but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1 assignment that precedes the loop, silently disabling HT mode for APs that append extra bytes to the HT Capabilities IE.
Severity
8.1 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < 37f642d47c3648a707df3ceb092eee1adffbfd28 (git)
Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < 8c872b47c7fc32e95e0da1db7512388794adcd69 (git)
Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a (git)
Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < 918537a0fbed85aab61fa28ad75e6279070610c9 (git)
Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < 6f91621fc45025ad3c0be796b70e6e4cee22fc69 (git)
Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < 225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d (git)
Affected: 554c0a3abf216c991c5ebddcdb2c08689ecd290b , < f8001e1a516ba3b495728c65b61f799cbfad6bd0 (git)
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Linux Linux Affected: 4.12
Unaffected: 0 , < 4.12 (semver)
Unaffected: 5.15.212 , ≤ 5.15.* (semver)
Unaffected: 6.1.178 , ≤ 6.1.* (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.96 , ≤ 6.12.* (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix OOB write in HT_caps_handler()\n\nHT_caps_handler() iterates pIE-\u003elength bytes and writes into\nHT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct\nHT_caps_element). Because pIE-\u003elength is a raw u8 from an over-the-air\n802.11 AssocResponse frame and is never validated, a malicious AP can\nset it up to 255, causing up to 229 bytes of out-of-bounds writes into\nadjacent fields of struct mlme_ext_info.\n\nTruncate the iteration count to the size of HT_caps.u.HT_cap using\numin() so that data from a longer-than-expected IE is silently ignored\nrather than written out of bounds, preserving interoperability with APs\nthat pad the element. An early return on oversized IEs was considered\nbut rejected: it would bypass the pmlmeinfo-\u003eHT_caps_enable = 1\nassignment that precedes the loop, silently disabling HT mode for APs\nthat append extra bytes to the HT Capabilities IE."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - A nearby attacker can transmit a crafted 802.11 association response over the air; WiFi management-frame injection requires radio proximity and is not routable.\nAC:L - A malicious AP controls the IE length, contents, and handshake timing, making the bit-clearing overwrite deterministic without a race or uncontrollable condition.\nPR:N - The frame is processed before WPA or 802.1X credential verification, and OnAssocRsp does not authenticate its source BSSID; no target privilege or network credential is required.\nUI:N - Mobile, embedded, and headless systems commonly associate or roam automatically, allowing an evil-twin AP to reach the handler without human action.\nS:U - The corruption affects host-kernel driver state without crossing a VM, IOMMU, sandbox, or other security-authority boundary.\nC:N - The primitive only AND-clears following HT and network metadata and cannot reach pointer-bearing fields; no secret-bearing read or attacker-visible disclosure path was found.\nI:H - The oversized IE causes up to 229 attacker-controlled bit-mask writes beyond the 26-byte array, corrupting live kernel HT information and saved network metadata.\nA:H - The attacker can repeatedly corrupt BSSID, SSID, rate, IE-length, and HT state to prevent association; on a WiFi-dependent controller or IoT device this can sustain total loss of connectivity."
            }
          ]
        }
      ],
      "providerMetadata": {
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/37f642d47c3648a707df3ceb092eee1adffbfd28"
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        },
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          "url": "https://git.kernel.org/stable/c/bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a"
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        },
        {
          "url": "https://git.kernel.org/stable/c/f8001e1a516ba3b495728c65b61f799cbfad6bd0"
        }
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64440",
    "datePublished": "2026-07-25T08:51:13.138Z",
    "dateReserved": "2026-07-19T15:36:31.788Z",
    "dateUpdated": "2026-08-17T04:55:42.056Z",
    "state": "PUBLISHED"
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  "dataVersion": "5.2",
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      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "staging: rtl8723bs: fix OOB write in HT_caps_handler()",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-64440.json",
      "version": "2"
    },
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Because pIE-\u003elength is a raw u8 from an over-the-air\\n802.11 AssocResponse frame and is never validated, a malicious AP can\\nset it up to 255, causing up to 229 bytes of out-of-bounds writes into\\nadjacent fields of struct mlme_ext_info.\\n\\nTruncate the iteration count to the size of HT_caps.u.HT_cap using\\numin() so that data from a longer-than-expected IE is silently ignored\\nrather than written out of bounds, preserving interoperability with APs\\nthat pad the element. An early return on oversized IEs was considered\\nbut rejected: it would bypass the pmlmeinfo-\u003eHT_caps_enable = 1\\nassignment that precedes the loop, silently disabling HT mode for APs\\nthat append extra bytes to the HT Capabilities IE.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/staging/rtl8723bs/core/rtw_wlan_util.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"37f642d47c3648a707df3ceb092eee1adffbfd28\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"8c872b47c7fc32e95e0da1db7512388794adcd69\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"918537a0fbed85aab61fa28ad75e6279070610c9\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"6f91621fc45025ad3c0be796b70e6e4cee22fc69\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"554c0a3abf216c991c5ebddcdb2c08689ecd290b\",\"lessThan\":\"f8001e1a516ba3b495728c65b61f799cbfad6bd0\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/staging/rtl8723bs/core/rtw_wlan_util.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"4.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.212\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.96\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H\",\"baseScore\":8.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.2}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/37f642d47c3648a707df3ceb092eee1adffbfd28\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6f91621fc45025ad3c0be796b70e6e4cee22fc69\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8c872b47c7fc32e95e0da1db7512388794adcd69\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/918537a0fbed85aab61fa28ad75e6279070610c9\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f8001e1a516ba3b495728c65b61f799cbfad6bd0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-07-29T06:53:08+00:00",
      "cve": "CVE-2026-64440",
      "id": "CVE-2026-64440",
      "initial_release_date": "2026-07-25T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: staging: rtl8723bs: fix OOB write in HT_caps_handler()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64440.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-08-07T17:00:24Z",
      "cve": "CVE-2026-64440",
      "id": "CVE-2026-64440",
      "initial_release_date": "2026-07-25T15:59:18Z",
      "product_status:known_affected": "197",
      "product_status:known_not_affected": "101",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64440",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64440.json",
      "version": "4"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.